Hey rdavis,
welcome aboard, as Old Salt would say

As some one who seems to always forget to use the "search" mode in this terrific website myself, I feel very qualified to help.

At the very top of the page you can click on "search". Fill out the parameters and you may find what you are looking for.

BTW, my advice is to search "depthfinders" and go into the "fishing tips". Pay particular attention to the advice that Kingfisher has on both fishing AND his depth finder set-up. There are pics here somewhere showing you how to do it. Top notch really and inexpensive. (don't waste your money on a smartcast)